Montana Field Guide

Taprooted annual. Stems erect, usually branched, 5–70 cm. Herbage glabrate; leaf margins sparsely retrorse-scabrous. Leaves cauline, linear, entire, petiolate below, 1–12 cm long. Inflorescence open leafy-paniculate with suberect branches. Involucre hemispheric, 5–10 mm high; phyllaries glabrous, linear-lanceolate, nearly equal, green, white-margined below, mucronate. Rays absent. Disk flowers ca. 14, filiform, white to pink; corollas 2–4 mm long; style well exserted. Achenes obovoid, 2- to 4-nerved, purplish, ca. 2 mm long (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Vernally wet margins of ponds, lakes, streams, tolerant of saline conditions; plains, valleys (Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

POLLINATORS
The following animal species have been reported as pollinators of this plant species or its genus where their geographic ranges overlap: Bombus vagans, Bombus bifarius, Bombus borealis, Bombus centralis, Bombus fervidus, Bombus flavifrons, Bombus huntii, Bombus mixtus, Bombus rufocinctus, Bombus sylvicola, Bombus ternarius, Bombus terricola, Bombus sitkensis, Bombus pensylvanicus, Bombus griseocollis, Bombus impatiens, Bombus insularis, Bombus suckleyi, Bombus bohemicus, and Bombus kirbiellus (Plath 1934, Heinrich 1976, Thorp et al. 1983, Colla and Dumesh 2010, Colla et al. 2011, Koch et al. 2012, Williams et al. 2014, Tripoldi and Szalanski 2015).